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Replacement of Auxiliary Belt Tensioner

Model: Mercedes Classe M W163 - Years 1997-2005
Part: V-belt

On Volkswagen Audi engines, it is quite common for the auxiliary belt tensioner to fail, becoming particularly noisy and producing a sound that may suggest a fault with the engine; replacing it is fairly straightforward, but you will need the appropriate spanner to remove the fan connected to the crankshaft pulley; once the fan is removed, loosen the tensioner and slide out the auxiliary belt; then unscrew the fixing bolts of the tensioner and the upper idler pulley; install a new pulley and a new tensioner, then insert the new belt.

Updated on 16 February 2026 by ScegliAuto

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